High-speed signaling system



May 22, 1928. 1,670,376

H. NYQUIST HIGH SPEED SIGNALING SYSTEM MIO/NE y May 22, 1928.

H. NYQulsT 1,670,376

man SPEED SIGNALING SYSTEM Filed May 13. 192s 4 sheets-sheet' 2 L N11" 73 l etettor.;

Y I T\ I NF i WOT JN VENTOR 4 Sheets-Sheet 3 Filed May 15, 1926 HIGH SPEED SIGNALING SYSTEM May 22, 1928.

Gen).

Jaures l 'ed May 2z, 192s.

H. NYQUIST HIGH SPEED SIGNALING SYSTEM 4 sheets-sheet 4 Filed May 15, 1926 1N www/e 22W alst By W C A TTORNEY Parental Mey 2z, i928.

eprice.

metastasis' stamane @ma .ohject ofrn'ypinven'tien is to provide .tfhe' speed ef transmission of V p ignaljs by utilizing simil'tnebusly we er more pnysieii distinguishable transmitting channels.' gnether .objectof my invention is" to' provide forA utilizing.' severa .channels for respectiveA messagesy or i' n veliv ion4 utilizing all these. channels siu nen'sl'y'ffor theY transmission: of one me )age at greater speed.- Another. object oi invention is to providelfor splitting .the phase ofya carrier current iand transmitting mankind Ichanges on one cmponent and.

\ spacing changes on the other component so as t increase the speed of transmission as cnpared' with' sending' both kinds o'f changes on' a single component. AThese obl and other objects of my invention will' becomel aiparent on consideration of .a limited nunfiber of specific examples of -pia'ctice 'ccdi'iig to' the invention which l. now prsoff:eedt tedisclosein this specification. .It win e@ understandin the renewing .disclosure relates to these particular examples ftli'ei'vention' and that the invention will be denediln'the' appended claims. 7

nte'rinij; tothe drawings, Figure 1' a diagram ofsend'ing' apparatus for one` niessagefon a carrier current of a certain fre: uenc'y decomposed into two components 90. degrees apart in phase;j Fig.' 2 is, a .diagrain ofi corres ending receiving apparatus in-n volviiig t `e use" of a frequency doubler; Figf is a" Ydiagram of alternative receiving apparatus employing two polar relays; Fig.` L is a diagiani efanother alternative l.form of receiving apparatus employingV aisingle b'iased'rel'ay; Fig. 5 is a diagram indicating newV more than twophysica'llv distinguish. able .transmitting channels can be utilized at the traiisrnitting'end for respectivemese sagev channels er alternatively` as av single message channel at' correspondingly increased spee'dgFilg; a' `diagrain for the' receiving endoorespnding to Fig. 5; Fig. 7 is a diaf gram of ai'systeI'inwhich' one channel. .or relatively high speed message sending and receiving apparatus is einplyed with two relatively low speed transmitting channels between' themg'ligv. 8 is a diagram of repairing ,apparatus alternative to shown 192'61 serial No. 108,940.

in F ig'. 7; and Fig-.9 isf a diagram `of a systcm in' which one channelof relatively lhigh Speed message sending and receiving `apparatus is. employedwith three relatively low speed transmitting channels" between them.

. Referring to Eig. l, -theoscillator atv the left `generates :in alternatingj current of a certain fundamentalfrequency which is de.'- livered to the harmonic generator whose out-l put-is accordin ;ly'v aco'inposit'e Vcurrent Aof various. frequencies all having harmonierelati'on to the fundamental. `This composite current goes, to theainplifier as shown ,in thev drawing, and its outputv goes to the busses ll' from. whichnrespective branches goto thejnpu'ts. of the variQusband-pass filters designated B. 1);. F, Each of these filters passesa respective band otfrequenc'ies'such as the band 0n the frequency j as indicated in the drawing.

The fp-hase splitter Ushown in ,FigE 1b is zi network havinglresis'tances and reac'tances of lthe magnitudes given by the legends in the drawing, n being, a positivereal number.. The :current from the phase' splitterlinthe conductor pair l2 referredtn 21s phase A,` will diil'er 10511.90. degrees from that. .in the conductor pair 13.,.freferred te as phas e, B7.;. Each p'air of. conductors leads to, a pair of opposite vertices ofaybrifdge having three of its four sides eachformedf by a resistance n., the fourth sidev beingppen. or closed as de.u termined by' the positionv of the armature of the relay 3 or 6.1 The remaining two'3 vertires of each .bridge areconnected :shown to the windings.1 4endif),v respectivel'y7 `of a hybrid coil-arrangement with a balancing network .on .one side` and a circuit to the band-pass .filter .16', on the `other side, I, r.lfhe outputl from-this lilter lgoes' to the bus-bars 17 and thence to the line,

. The relays 3 and 6 have already been.inen-` tioed. They arecntrolld by thehey K through A4.the relay R.v and the circuits as shown in. the.drawing. l ,M

. 'Ihearrnatures .o the polarized.,relays, l, 2, 3, 4., .5 and @are all. designed tqremain on whichever cntact Athey are resting when the windings are deenergized'; VAs shown in the "drawing, current Sl .HOW-ing, rQ the battery through the Contact S lQ'Wn through relays l, 2 and 3, and this direction of currcnt has moved the corresponding armatures up as lshown. Closure of the key K energizes relay R and moves its armature to the marking contact M, which puts current down through relays 4, 5 and (5, causing their armatures to shift down from the positions lshown in the drawings. This opens the previously short-circuited arm of the bridge in phase B and also reverses the circuit for relays l, 2, and.

lVhen the key K is released and current; again flows through the spacing contact S, it will go through the relays 3, 2 and l in the reverse direction to that previously cousidered. causing their armature to go down. but the armatures of relays 4, and 6 will remain down. The shift of the armature of relay opens the previously short-circuited fourth arm of the bridge on phase A and the shift of the armatures of relays l and 2 reverses the circuit for relays 4, 5 and 6.

The next depression ot' the key K sends current through contact M and through relays 6, 5 and 4 lin reverse direction to that of their previous energization. Accordingly, their armatures go up but the armatures of relays l, .2 and 3 remain down. rfhe movementi of the armature olf relay 6 again closes` the fourth arm of the bridge for phase l5 and the movement ot the armatures of relays l and 5 again reverses the circuit for relays l, 2 and The next time the key K is released, current flows through the spacing Contact S down through the relays l, 2 and 3 causing their armatures to move up; it will be seen that this completes a cycle and brings the armatures of relays l, 2, 3, 4, 5 and G all back to their positions as assumed at the outset and shown in the drawings.

lt will be seen that two cycles of' movement of the key K give only one cycle of movement for each of the armatures of the relays l, 2, 3, si, 5 and 6. The order ot' operations is as follows, referring to the opening and closing of the fourth arm ol the bridge for the phases A and B;

First markopens on -phase B;

tipacc thcreaflew-opens on phase A:

Second markcloses on phase B;

Space thereafter-closes on phase A.

'l'hc current in the coils 'll reverses in phase when the fourth arm of the bridge for phase A is changed from open to closed or from closed to open. 'lhus each shift of an armature or relay 3 or (3 causes a phase reversal of one of the two QO-degree components of eurrent'in the input to the filter 1G. The composite current in the input to this filter, being the sum of the two phases. changes by degrees when one of its phases is reversed. Therefore, the elfect on this composite current produced by repeated operation Of the key K is each time to shift the current progressively 90 degrees in phase as indicated by the diagram ot Fig. 'i'.

lt will be seen that in the repeated opera tions of the key K all the markimr is initiated by phase reversals oii one ol tue two SNL degree components, and all the lspacing is initiated by reversals oi the other component of current. Hence whatever the limit ing speed for reversing one ot these two components, the message lspeed will be twice as great as it would be if one message were sent on one such component.

Other messages may be sent in the mme way on other frequencies by the use of similar apparatus as indicated symbolically in Fig. l at Qi and 2i. all such lretpiem'ies bcin'g superposed on the line. The reactaiues` in Q1 will have diil'erent values. appropriate to the respective Jfrequencies.

The line currents may be received with apparatus corresponding to the diagram ot Fig. The band-pass lilterlS passes the band ot' current of the carrier frequency f and applies it to a frequency doubler whose output is accordingly a current ol frequency 2f. It has already been mentioned in connection with Fig. 7 how each shift of the sending key K causes a Utl-degree phase shift in the compositel transmitted current. In the frequency doubler such a phase shift in its input will cause a phase reversal in its output current.

The oscillator shown at the right ol? Fig. is synchronized by methods well known in the art, so that its frequency corresponds with the frequency of the generating oscilla tor at the sending end. lts current output goes to a harmonic generator whose output in turn goes to an amplifier, and t'rom thisl amplifier component currents of all harmonic. frequencies are put on the bus-hars ttl. The band-pass lilter i2() takesl oll` current o` the frequency 2f and passes it, through the adjustable phase shifter shown in thc drawmg'.

'lhe outputs from the frequency doubler and the phase shifter are superposcd `in the input ol' the detector. lt has already bccu mentioned how the output from thc ircquency doubler reverses in phase l'or each signal change t'rom spacing lo marking or `from marking to spacing. ln omI ol' (hcw state-s tln` two inputs to the detector will la` in phase and in the other state they will bc in phase opposition. lhen they are in phase, the detector output current will he greater than when they are in plnue opposition and the armature ot the biased polar relay in the detector output circuit will be shifted accordingly and the messages will be indicated in the sounder controlled by the armature of this relay.

An alternativiA receiving system is shown in Fig. 8. 'lwo detectors 225 and Qlarc arranged as shown, and their grids are supill) lou

y in

source .is at.

i `erogare plied with electroniotiye forces from a local iloiirie oetiieqiien y and 90 degrees apart in pini Snperposed 'alike in the grideircuits or the 'tty-o de'te s '23 iid 24, electron'iotive tort-es are also applied Vcorresponding to the received signal currents offrecliiency f.

Of the Vtwo coi'npoiients receivedfover the line through 'the hand-pass lllter, both of frequency and d iffeiingin,phaseQO degreefs, one of them will be in phase with the local elec-tromotive force to `one of the detectors or in phase opposition, and similarly, -thevotlier received component will he in phase with thejlocal clectrozinotifve force to the `other detector or in pliasef opposition. their Ireceived phase A' agrees with the local source o n detector 3, the corresponding reley a-rmautre A. will operated one way, hut if the relation is a phase opposition, the said armature `will be operated the other way.k Thus the polar relay `arinatui'e A respondsto the reversals onphase A and the polar releynrmeture B respondsto the re yersals on the other phase/ 13.

By "the circuit shown Fig. `3;, thesevtwo armatures control the non-polar relay 31, whfiehyin turn controls the sounder.

` Reiiieinhering the character of' the transinit-tyd currentjand that its two components reverse alternately, it will he seen that the arn'iatures A and B are operatedalternately.

l'hen they are both on ground orhoth on .haiti ery, the sounder circuit will he open, hut when one armature A or Bis on battery and the other on ground, their the sounder circuit will he closei'l. Thus the operation will correspond to the operation of the key K at the sending end.

Still another alternative receiving system is shown in Fig. Ll. 'liithis caseessingle dcL Lector isengililoyed and the-phase ofthe local usted so that the corresponding electreimiitive toice-onfthe detector grid isiii phzwe-or phase opposition with the line eleclo ire 'forceV wl'ieiii la mark is heilig nttted. W'hen 'they are in phase, the nltaiit detected current is of lsu'licient itude to operate the vrelay in the der oi plate circuit and close the sounder circuit. Un the .next space, the line `current is f-:hilited 90 degrees relative Vto the local source and the detector plate circuit `current is reduced. The res ance in series with the biasing winding oi? the relay is'so adjusted that-the biasing current neutralizes-theeifect ci the plate circuit:currentnnder this condition andthe receiving 4relay releases itsariiiiatujre `and'opei'isythe vsoiinder circuit. On ythe ne3it"inarl, the line and local currents are il degrees outof yphase and the detector plate circuit current still further reduced, setlist thereleyis again operated loeeause ot the current `inithe `biasing winding. On -tli next space, tlie phases are again 90 deart and the relay armature 4is re- "ll'h le oljoperationsfiepea"ts,fthe operating on `every mark and `i"cng on every space transmitted Jfrom the sendiijig;` station. In the ttoregijoing exaniplesof practice ziccerding to my invention, two .physically distii uishahle channels have heenutilized tor asingle message, so thatior iii-given limiting speed in each channel, the message speed is twice as great as if the message were Vtra-'nsniit'ted Vin only a single channel. It `still `greater speed is desired, more than two physically ('l'istinguishable impulse transmitting channels can 'le employed 'for one 'niesage channel. In Fig. 5 I have shown one mesw sage channel associated in this way with grees ap ,.1

tour physically distinguishable Vimpulse transmitting channels. The hey K controls in turn controls two others inthe saine way,

that isthe armature of 'relay 3 controls armatures Q5` and 2G, and the laririatui'e ofrelay 6 controls armatures 27'and 2S.

The 4twoarmatures '27 and 28 control the two phases on frequency f j'nst `the same as the armatures of relays 3 and 6 'ott Fig, 1 control the two phases on frequency in thaty ligure.` Similarly, the two armatures and 2G control the -two phases of current of frequency f. It will readily be seen "that t 'ie arrangement is such that Iwhen thekey l is operated `from the position vshown in Fig'. '-7 Y First finarh reverses phase A on frequency i' i n lilollowingir space reversesI` pliese A on ircl l l YV .Y Y l l `queiicy f quency f.

K this cycle repeats. Thus it will beset-u that four channels are utilized and that these channels are affected in cyclic order 'lhy the operation `ofthe signaling` key so that. each channel affected only `once iii a `cycle of four operations et the key. Accordingly, 'i'ior a :given limiting` speed in each channel, the message `speed will he 'tour ti' "iles as li` jreat with the system of Fig. i'tt'ithe 'trans mission w re Wholly on one channel.

By throwing the 4'tour pairs of switches at Q9 and usine the `four keys 30. four indepeni1 nt `mes v:res eanhe sent en respective channels, `butin this Lcase the :limiting speed For 'further operation of the hey' wir die

CII

in each channel will make the signaling speed only a fourth as much -as when the tour channels are used for one message.

A receiving system is shown in Fig. G for cooperation with the sending system in Fig. 5. It will he seen that it comprises two receiving units like the system ot Fig. B, but whereas the armature ot' relay 31 of Fig. 3 directly controls a sounder circuit, the two corresponding armatures ot relays 31 and ill ot Fig. G cooperate in the control of another relay 3Q. which in tur'n controls a sounder. The combined operation ol' the armatures` of relays 31 and 81 in control ot the armature of the relay 32 in Fig. o' is the same as the combined operation of arma tures A and B in control ot thi` armature oi relay 31 in Fig. 3.

lVhen the switches 29 are thrown at the sending end (Fig. 5) thus providing for usev of the four keys 30, then at the same time the switches 33 will be thrown at the receiving end (Fig. 6), so that the four keys will the windings the armature will remain on the contact on which 1t 1s placed. The windings of 1,9 and 3 are connected in series as are also those of 4, 5 and G; and 6 are signaling relays on the two independent channels, respectively. Relays 1 and 2, together, act as a double-pole, double-throw switch and reverse the windings 4, 5 and 6 in the circuit on each ope ation; 4 and 5 act similarly on 1, 2 and Batteries and grounds are connected as shown in the drawing. `At the receiving terminal, the receiving relays 111 and 112 follow the signals sentover channels 1 and Q by relays 3 and respectively. The. armatures ot these rc Vceiving relays. with batteries and grounds shown, operate the receiving relay R, in the high-speed channel and this in turn operates the subscribei"s sounder S1. It an be seen that R is on space7 when the two-channel receiving relays a re both on mark or both on space and on mark when only one of the receiving relays is on mark The action of this system is best understood by following the sequence of operations through a complete cycle of changes. At the start, it is assumed, as shown on the drawing, that K is open, T is on space, 1 to 6 are up, say, putting 3 and 6 on space so that 111 and 112 are accordingly on space with R and S consequently on space. The follow ing table gives thc positions of the various relays as K is successively closed and opened. (M denotes mark and S space.)

The second space after the sta rt returns the system to its original condition, completing the sequence of the operations. It can be seen that S follows K exactly, but that relays 3 and 111 and 6 and 112 complete only one cycle for two on K and S, thus cstablishing a channel from T to R twice as fast as either of the line channels 1 and i2. As previously exemplitied, a continuation ot this process allows the use of any power ot two channels (that is, 2, 4, 8, 16 and etc. channels) with the consequent gain in speed for the derived channel.

The receiving apparatus shown in Fig. 8 is alternative to that of Fig. and its resultant operation is the same, as will be readily understood from the drawing.

As has been remarked, the principle of the foregoing described systems can be ex tended to utilize f2, 4, 8 or any power of 2. channels for one message channel. Fig. t) shows ar system that 1s good for utilizing 3 channels and it will be seen that its principle can be extended to utilize 5, 7 or any odd number of channels.

At the sending terminal, T is operated hy K as before and puts positive battery Afor mark7 and negative battery for space` on the star terminal O of the high-speed channel. Polar relays 1-6 are connected as shown in the drawing and it is understood that any of them is operated to mark by current from positive battery and to space by current from negative battery. Relays 1 to 3 are so adjusted that any of their armatures remains on the contact on which it is placed with no current in the winding. Relays 1 and L1. Q and .5, and l and t. work together in pairs. Relays 1 to il are signaling relays on the three channels 1 to Il. respectively, use being made of the M and S contacts on one o1' the armatures for this purpose. Relays t to 6 serve to distribute the signals transmitted by T to the three channels in order, the first mark going to channel 1, say, the first space to channel 2, the next mark to 3, etc. This arrangement may be easily extended for use on a larger number of channels; and if the number used is odd, the signal sent to any signaling relay on successive cycles of distrlbution always such as t0 operate it to a cycle of operations.

` As pointed out above,

its uncoupled contact. andl so maintainl the distributionl At the. receiving terminal, the three-channel receiving relays lll to 113 follow the signals sent on` channels l to B-by relays 1 to 3, respectively. t These are con.- nected, as shown, to R and S in the highspeed channel in such ai way that a reversal of either channel relay causesV a reversal of R and S. rlhe following tableA gives the positions of the various relays during a completel cycle of operation or' the system, the starting. condition. being assumed as shown in the drawing. (M denotes mark andA S space as before.)` v

Signal K 'l l 1, 4, 111 2, 5,112 3, 6, 113 R and S Open S S M S S Closed M M M S M Open.; S M S S S Closed. M Ml M M Open S S S M S Closed M S M M M Open S S M S Y S The third space after starting returns the system to its original condition, completing 1t is seen that S fol-y lows K exactly, but the line channels are operated at only one-third of the speed used on the high-speed channel between K and S.

this system of distributing signals over channels can be' easily extended to include any odd number of channels. The receiving system canbe enlarged to include any number `of channels.

A proper combination of the two methods signaling indicated in Figs. 7 and 9 allows the distribution of the signals on one telegraph channel over agroup of channels of any `desired number with a corresponding gain in the limiting signal speed of the original channel.

l. The method of high speed signaling, which consists in transmitting successive signal impulses over different physically distinguishable channels in cyclic order.

2. The method of high speed signaling, which consits in transmitting successive signal impulses over-different physically distinguishable channels in cyclic order, and at the receiving end applying these impulses as receivedv over the different channels in the same cyclic order to operate a message receiving indicator.

3. The mehodV of highy speed signaling, which consists in transmitting a plurality of different Wave trains, and varyingthese wave trains in cyclic order by successive signal changes.

4. ln combination, means to transmit energy over several physically distinguish. able channels, and signaling means to affect these channels in cyclic order.

5. In combination, means to transmit vcarrier current of a i of4 the'.` key,

sponding to said carrier current components asqaiifected bythe operation of said` key,

means at the receiving end to detect the phase` reversals on each componen@ and means Ato indicate therefrom the message corresponding to the operation of the key.

7. In combination, means to generate a carrier current of a certain frequency, means to split it into two components differing in phase, a signaling key, means operated by said key to effect phase reversals of said components alternately at successive operations of the key, rent components as affected by the operation of the key from the transmitting station to the receiving station, a synchronized source at the receiving station for electromotive forces in phase or in phase opposition with the respective components of the transmitted current, detecting means responsive conjointly to the received current, and the current from the local source, and a signal indicator controlled by said detecting means. y

8.111 combination, a line, means to generate carrier currents and superpose them on the line, means to split each such current into two components 90 degrees means for each component, a key, and means operated by the key to actuate the said phase reversing means alternately at each key'operation for each component.

9. The method of high speed signaling, which consists in sending successive signaling impulses on different channels in cyclic order, whereby the speed on each channel is less than if all the impulses were sent on one channel.

l0. In combination, means fortransmitting energy in a plurality of channels, re- .spective means at the sending end for changmg the energy in each channel, means at the receiving end for detecting these changes, a plurality of independent ey's respective to said means at the sending end, a single key, means to operate said means at the sending end cyclically by said single'key, and switches alternatively to connect said plurality of keys or said single key in operative relation to said means at the sending end.

means to transmit said cur-` of various frequencies apart in phase, phase reversing lll() 11. ln combination, means for transmitting energy in a plurality of channels5 respective means at the :sending` end for chang'- ing the energy in each channeh means at the receiving end for detectingthese changes. a plurality et' independent keys respective to said means at the sending end. a single hey. means t0 operate said means at the sendingjr end cyclically by said single key, a plurality of respective signal indicators at the receiving end, a single signal indicator at the receivinglr end, means to aetuate the single signal indicator' by the received energy changes in cyclic. order, and switches operatively to connectsaid plurality of Signal indicators or said single indicator.

12. A multi-channel energy transmitting system and alternative means to send and receive one message utilizing all the channels in cyclic. order or to send and receive independent messages on the respective channels.

113. 'l`he method ol higrh speed signalinf. which con it-1 in transmitting sncccssive. signalimpnlses over dill'ercnt physically die-'- tingrnishable channels in cyclic. order. each signal impulse pers tine'` in a train-mating channel till the arrival oi the next cyclic turn oi' that channel.

14. The method of high speed signaling, which consists' in trans iitlin;r successive signal impulses over dill'erent physically distinguishable chanmls. each signaling." ine pulse persisting in a channel till the next occasion for usine' that channel.

In testimony whereof. lv have signed in r naine to this specification this (3th day of May, 192e.

HARRY NYQlIS'l. 

